<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		
		
		<script type="text/javascript">
			var m = '3';
			var n = 3;
			if (m == n) {
				console.log('m==n');
			}
			if (m === n) {
				console.log('m===n');
			}
			
			var str = "Hello jS!";
			console.log(str.length);
			console.log(str.toLowerCase());
			console.log(str.charAt(4));
			console.log(str.indexOf('o'));
			
			var str2 = 'how are you today';
			var array = str2.split(' ');
			console.log(array);
			
			if (0) {//false
				console.log('0')
			}
			if (!0) {//true
				console.log('0')
			}
			if (1) {//true
				console.log('1')
			}
			if ('') {//false
				console.log('空字符串')
			}
			if ('aaa') {//true
				console.log('aaa')
			}
		</script>
	</body>
</html>